There are numerous medical and surgical procedures wherein el electrosurgical probes are used to cut and/or cauterize tissue. Numerous monopolar and bipolar electrosurgical probes are available on the market today. Electrosurgical probes typically comprises a probe tip that is permanently or releasably attached to a handpiece. The handpiece is sized and configured to be grasped by the human hand. The probe tip typically extends distally from the handpiece. The distal end of each probe tip typically has a specific shape (e.g., straight, curved, hook shaped, looped, square, ball, spatula, needle, ball, L-shaped, forceps, clamps, etc.). The probe tip typically incorporates one or more electrodes that, when energized, cause the probe tip to heat. The handpiece may be adapted for connection to an electrosurgical signal generator, which provides energy to heat the probe tip. In some cases, insulation may surround all but the distal-most end of the probe tip to prevent peripheral tissue damage or capacative couplance. In many cases, the temperature of the probe tip is variable and may be controlled by a rheostat or other apparatus for varying the amount of electrical current that passes through the electrode(s) at the probe tip. Examples of electrosurgical generators, handpieces and/or probe tips include those that are commercially available from Bovie Medical Corporation, St. Petersburg, Fla.; Hi-Top/W. J. Surgical, Elizabethtown, Pa., ValleyLab Division of Tyco Healthcare Group LP, Boulder, Colo. and ProSurg, Inc., San Jose, Calif.
While the electrosurgical probes of the prior art have been used to cut many different types of tissue, there are still certain surgical procedures wherein electrosurgical probes have not been used due to concerns about inadvertent burning or damaging delicate nearby tissues.
One example of a procedure that has heretofore not typically been performed using electrosurgical devices is the removal of epiretinal membranes from the eye. An epiretinal membrane (sometimes referred to as macular pucker, premacular fibrosis or surface-wrinkling retinopathy) is an abnormal, transparent or translucent, collagen-containing membrane that forms between the inner limiting membrane of the retina and the cortex of the vitreous body. As the epiretinal membrane contracts, it causes the retina to become distorted or wrinkled thereby disturbing the patient's vision. Visual symptoms may vary from very mild symptoms to very severe symptoms. Patients may experience blurred vision or loss of central acuity. Patients may also experience distorted vision In which straight lines appear to be bent or curved; or objects appear to be distorted in shape and form. Rarely, epiretinal membranes can damage the retina so severely that the patient can almost lose central vision and only see with their peripheral vision.
The treatment epiretinal membrane generally involves surgery to remove the epiretinal membrane. In such surgery, an ophthalmologic surgeon initially performs a vitrectomy wherein a vitrectomy cutter is used to remove the vitreous body from the posterior chamber of the eye. After the vitreous body has been removed, the surgeon gently peels the epiretinal membrane off of the surface of the retina using fine instruments. The epiretinal membrane may be attached to the retina at discrete attachment points. Thus, the peeling of the membrane from the retina can result In some undesirable tugging or traction on the retina with potential tearing and bleeding of the retina, or even local detachment of the retina. After the epiretinal membrane has bees successfully removed, the macula typically flattens out and the patient's symptoms slowly improve. The majority of patients get improvement of vision following the operation, however some distortion of vision and/or loss of visual acuity may remain post-surgically.
At present there remains a need in the art for the development of new electrosurgical devices that provide for control over the area In which heat generated by the device can cause substantial cutting and/or coagulation of tissue, thereby elimination unwanted collateral damage during the procedure.